📚 Documentation: Add README, API documentation, and setup instructions

[ManvithGopu13]

Missing Documentation

Current State:

• ❌ No README.md file
• ❌ No API documentation
• ❌ No setup/installation instructions
• ❌ No environment variable documentation
• ❌ No usage examples
• ❌ No contribution guidelines

Required Documentation:

1. README.md should include:

   • Project description and purpose
   • Features overview
   • Installation instructions
   • Configuration (environment variables)
   • Usage examples
   • API endpoints overview
   • Development setup

2. API Documentation should include:

   • Endpoint descriptions
   • Request/response formats
   • Example requests/responses
   • Error codes and meanings
   • Authentication requirements (when implemented)

3. Environment Variables documentation:

   • FLASK_DEBUG
   • KAGGLE_USERNAME / KAGGLE_KEY
   • CORS allowed origins
   • Output directory configuration
   • Model configuration

4. Setup Instructions:

   • Python version requirements
   • Dependencies installation
   • Kaggle API setup
   • Running the application
   • Testing

Recommended Tools:

• Use OpenAPI/Swagger for API documentation
• Add docstrings to all functions
• Include code examples in README

Priority: Low
Type: Documentation